Fruit tree and vine sprayer calibration based on canopy size and length of row: unit canopy row method

A sprayer calibration method for fruit trees and vines, based on height and width of canopy, and row length is presented. Using a unit canopy 1 m high x 1 m wide x 100 m of row length as the basis for calibration, means that area and row spacings are not required as parameters in the formulae. The whole approach is based on just one simple formula, which adjusts water volume to canopy size. Since the method adjusts spray volume and chemical dose more accurately without changing the average dose obtained on foliage, there are no changes in the information required for the registration of agricultural chemicals. The technique can be used with existing label information. However, for concentrate spraying recommendations, we propose that the industry work towards pesticide labels that provide chemical rates/100 m of unit canopy, and that rates/ha be deleted. The need for adjustments for canopy density, canopy type and sprayer type are also discussed. The method appears simpler and easier to understand than current tree-row-volume methods based on m(3) of canopy/ha, which have not been widely adopted. (C) 1998 Elsevier Science Ltd. All rights reserved.